Electronic handwriting is increasingly important in a variety of contexts. For example, electronic handwriting is now commonly used in place of pen and paper to obtain a credit card holder's affirmation of a credit card transaction. As electronic handwriting has become more common, the ability to verify authenticity of electronic handwriting has also become more important.
U.S. Pat. No. 6,487,310 describes an “elastic matching” method for comparing one signature against another, comprising the operations of creating a mapping between corresponding points in two signatures to be compared measured at different times after the commencement of writing the signatures which maximizes the correlation between the local spatial neighborhood of the measured points and simultaneously minimizes the curvature of the elastic spatial distortion from the mapping, providing quantitative measures of both the degree of the spatial correlations and the degree of the non-uniform spatial distortions in the mapping, thereby providing measures of the similarity between the signatures.
In addition to the accuracy of signature verification, the recording of handwriting data is an important topic. Recent handwriting input devices are not limited to conventional digitizers and there are many types of hardware having similar—but not identical—capabilities. In order to ensure the compatibility of handwriting data captured by all types of devices, a flexible data format is desirable.